diff --git a/README.md b/README.md
index abb64ed..96d995f 100644
--- a/README.md
+++ b/README.md
@@ -179,14 +179,14 @@ utoipa = "5"
 <details>
   <summary><b>Conversions</b></summary>
 
-- `std::io::Error` → Internal  
-- `String` → BadRequest  
-- `sqlx::Error` → NotFound/Database  
-- `redis::RedisError` → Service  
-- `reqwest::Error` → Timeout/Network/ExternalApi  
-- `validator::ValidationErrors` → Validation  
-- `config::ConfigError` → Config  
-- `tokio::time::error::Elapsed` → Timeout  
+- `std::io::Error` → Internal
+- `String` → BadRequest
+- `sqlx::Error` → NotFound/Database
+- `redis::RedisError` → Cache
+- `reqwest::Error` → Timeout/Network/ExternalApi
+- `validator::ValidationErrors` → Validation
+- `config::ConfigError` → Config
+- `tokio::time::error::Elapsed` → Timeout
 
 </details>
 
diff --git a/src/convert/redis.rs b/src/convert/redis.rs
index 6465a05..8494ae3 100644
--- a/src/convert/redis.rs
+++ b/src/convert/redis.rs
@@ -4,13 +4,14 @@
 //!
 //! ## Mapping
 //!
-//! All Redis client errors are mapped to `AppErrorKind::Service`.
+//! All Redis client errors are mapped to `AppErrorKind::Cache`.
 //! The full error string from the driver is preserved in `message` for logs
 //! and JSON payloads (if applicable).
 //!
-//! This categorization treats Redis as an infrastructure/service dependency.
-//! If you need a stricter taxonomy (e.g. `Cache` vs `Queue`), introduce
-//! dedicated `AppErrorKind` variants and adjust the mapping accordingly.
+//! This categorization treats Redis as a cache infrastructure dependency.
+//! If you need a different taxonomy (e.g. distinguishing caches from queues),
+//! introduce dedicated `AppErrorKind` variants and adjust the mapping
+//! accordingly.
 //!
 //! ## Example
 //!
@@ -26,7 +27,7 @@
 //! let dummy = RedisError::from((redis::ErrorKind::IoError, "connection lost"));
 //! let app_err = handle_cache_error(dummy);
 //!
-//! assert!(matches!(app_err.kind, AppErrorKind::Service));
+//! assert!(matches!(app_err.kind, AppErrorKind::Cache));
 //! ```
 
 #[cfg(feature = "redis")]
@@ -35,15 +36,30 @@ use redis::RedisError;
 #[cfg(feature = "redis")]
 use crate::AppError;
 
-/// Map any [`redis::RedisError`] into an [`AppError`] with kind `Service`.
+/// Map any [`redis::RedisError`] into an [`AppError`] with kind `Cache`.
 ///
-/// Rationale: Redis is treated as a backend service/cache dependency.
+/// Rationale: Redis is treated as a backend cache dependency.
 /// Detailed driver errors are kept in the message for diagnostics.
 #[cfg(feature = "redis")]
 #[cfg_attr(docsrs, doc(cfg(feature = "redis")))]
 impl From<RedisError> for AppError {
     fn from(err: RedisError) -> Self {
-        // Infrastructure/cache issue -> service-level error for now
-        AppError::service(format!("Redis error: {err}"))
+        // Infrastructure cache issue -> cache-level error
+        AppError::cache(format!("Redis error: {err}"))
+    }
+}
+
+#[cfg(all(test, feature = "redis"))]
+mod tests {
+    use redis::ErrorKind;
+
+    use super::*;
+    use crate::AppErrorKind;
+
+    #[test]
+    fn maps_to_cache_kind() {
+        let redis_err = RedisError::from((ErrorKind::IoError, "boom"));
+        let app_err: AppError = redis_err.into();
+        assert!(matches!(app_err.kind, AppErrorKind::Cache));
     }
 }